As we mentioned before, one of the design goals of BRITE was to combine strengths of available models into a single tool. BRITE incorporates an ImportedFileModel class deriving from the base abstract class Model. Figure 6 shows the current structure of the ImportedFileModel.
The Generate method associated with a model derived from ImportedFileModel will be in charge of parsing a file in the format of the corresponding imported topology, and it will load it into BRITE Graph data structures. Once such a topology has been parsed and loaded, it can be used as a native BRITE topology. We have applied this approach to combine topologies from existing generators with topologies generated with a variety of other models. There are many useful scenarios where a researcher may benefit from having such a capability. For example, we could generate a top-down hierarchical topology, where the AS-level topology has been imported from NLANR topological data, and the router-level corresponds to Waxman topologies or topologies generated by the GT-ITM generator. It is also possible to generate hierarchical topologies with more than two levels. For example, a four-level topology may be obtained by recursively generating a top-down hierarchical topology where the AS-level corresponds to a Transit-Stub topology generated using GT-ITM and the router level topologies correspond to a top-down topology generated using BRITE. Thus, BRITE's architecture allows a researcher to combine topologies incorporating diverse research themes, as well as to create new models specific to certain scenarios.
The available models in this category are:
We are currently working on importing topological data from the CAIDA project, such as the data gathered by Skitter .